Back to EveryPatent.com
United States Patent |
5,036,537
|
Jeffers
,   et al.
|
July 30, 1991
|
Geographic black-out method for direct broadcast satellite system
Abstract
Television programs are broadcast to a plurality of receiver units in
various geographic areas. Each unit has a memory for storage of a
designation code representative of its location and a memory for the
storage of a blackout tier indication. Prior to the transmission of the
program to be blacked out, each unit is separately addressed and provided
with a message including a designation code for storage. Then, a globally
addressed message provides all receiver units having a selected
designation code with a blackout tier indication for storage. A program
tier indication is transmitted along with the program to be blacked out.
Each unit, upon receiving the transmitted program, compares the
transmitted program tier indication and the blackout tier indication in
its memory. All receiver units having a stored blackout tier indication
which matches the program tier indication are simultaneously prevented
from displaying the program to be blacked out.
Inventors:
|
Jeffers; John M. (Downsview, CA);
Mundy; S. Wayne (Brampton, CA);
Knight; Stephen P. (Markham, CA)
|
Assignee:
|
General Instrument Corp. (New York, NY)
|
Appl. No.:
|
036159 |
Filed:
|
April 3, 1987 |
Current U.S. Class: |
380/241; 380/242; 725/28; 725/68; 725/104; 725/132 |
Intern'l Class: |
H04H 001/00 |
Field of Search: |
380/20,21,43,48
358/349
455/2,3-5,31-33,12
|
References Cited
U.S. Patent Documents
3716654 | Feb., 1973 | Hendrickson et al. | 455/2.
|
4292650 | Sep., 1981 | Hendrickson | 358/114.
|
4323921 | Apr., 1982 | Guillou | 358/114.
|
4337483 | Jun., 1982 | Guillou | 358/114.
|
4354201 | Oct., 1982 | Sechet et al. | 358/114.
|
4484027 | Nov., 1984 | Lee et al. | 178/22.
|
4494142 | Jan., 1985 | Mistry | 358/114.
|
4531020 | Jul., 1985 | Wechselberger et al. | 358/122.
|
4536791 | Aug., 1985 | Campbell et al. | 358/122.
|
Primary Examiner: Buczinski; Stephen C.
Assistant Examiner: Gregory; Bernarr E.
Attorney, Agent or Firm: James & Franklin
Parent Case Text
This application is a continuation of U.S. patent application Ser. No.
672,925 filed Nov. 19, 1984 and now abandoned.
The present invention relates to direct broadcast satellite systems and,
more particularly, to a geographic blackout method for use with such
systems in which all receiver units within a given geographic area are
simultaneously prevented from displaying a program to be blacked out
through the use of a single command sequence.
The availability of small, low-cost television receive-only terminals in
recent years has resulted in an increasing demand for direct broadcast
satellite services. Such services include Pay-TV, tele-conferencing,
tele-seminar, private broadcast networks, and the like.
Unlike land lines and terrestrial microwave links, satellite transmissions
lack privacy. Such transmissions can be received by any TV receive-only
terminal whose antenna is situated to receive the satellite signals.
Accordingly, secure transmission of video and audio programming and data
signals is required to provide the privacy essential to many applications.
A simple example of a direct broadcast satellite network in which security
is required is one which broadcasts television signals to paying
subscribers. Since any receiver having an antenna in the broadcast area
can receive the satellite signals, it is necessary that the signals be
coded in a way which can be decoded only by the subscriber's receivers.
Certain subscribers may have paid for certain programs or program groups,
whereas others may have paid for other programs or program groups. The
signals must then be further encoded such that subscribers who have paid
for particular programs or groups of programs can receive same, while
other subscribers cannot.
In addition, it may be desirable to design the system such that a
particular subscriber can preview a program and then decide whether he or
she wishes to watch the program and, hence, pay for the privilege. In such
an impulse pay-per-view system, the decision of the subscriber must be
recorded and communicated to a billing facility for appropriate billing.
In such instances, the control signals to the subscriber's receiver
instructing the receiver how to communicate with the billing office must
be secure in order to eliminate the possibilities of theft of the service.
In the direct broadcast satellite system in which the present invention is
used, programming is distributed through a composite television signal
which includes a plurality of levels of programming called tiers. Each
tier carries a different variety of programming. A particular program may
suit several tiers, much like a library index card listing having several
possible topics of interest. Thus, a particular program may appear on one
or more tiers.
Each tier is assigned a number. The tier number is represented by a bit
stream. The bit stream is a series of zeros with a one at the bit
corresponding to the tier number. This is referred to herein as the tier
indication. If there are, for example, thirty-two tiers, tier number three
is represented by a bit stream of two zeros, a one, and twenty-nine zeros.
Each program is distributed along with a program tier indication which is
a similar bit stream with a one for the bit corresponding to the tier on
which it is distributed. The program and the accompanying program tier
indication are distributed to all receiver units.
Certain programs, whether paid for by subscription or on an impulse
pay-per-view basis, may be considered by the subscriber as inappropriate
for viewing by the household or certain members thereof. Such programs
may, for instance, include violent or sexually explicit movies or the
like. It is therefore desirable that the satellite system incorporate a
means for blocking out the tiers on which such programs are distributed so
that they cannot be decoded and displayed by the subscriber's receiver
unit. It is preferable that objectionable programming be blocked even if
the receiver unit is instructed to display the program as a pay-per-view
item. One way to achieve this is to control individual receiver units by
the system operator from the transmission end to block programs and
provide a mechanism whereby the program tiers designated for blocking can
be changed upon written or telephone communication by the subscriber with
the system operator.
Further, there are certain instances where it is necessary to black out
programming in a particular geographic area. For example, certain sporting
events such as baseball games, football games, boxing matches, and the
like, are provided to the satellite network for broadcast with the
restriction that they not be distributed within the locality in which the
sporting event is taking place, so as not to adversely affect attendance
at the arena. It is therefore necessary that the satellite network have
capability for blacking out selected programming in certain designated
geographic areas.
In broadcast television, local blackouts are achieved simply by not
broadcasting the program over any local affiliate television station in
the area to be blacked out. In a direct broadcast satellite delivery
system, local area blackouts may be achieved by selectively addressing
each subscriber receiver unit in the subject geographic area and then
selectively preventing each of the addressed subscriber receiver units
from displaying the particular program.
However, since there may be a great many (perhaps millions) different
subscriber receiver units located within the geographic area to be blacked
out, it may require many minutes or more to sequentially address all of
them to achieve the appropriate blackout. A significant time lag, that is,
more than tens of seconds, is undesirable since the program prior to the
event to be blacked out is typically not blacked out. Thus, if the
blackout sequence is begun prior to the transmission of the program to be
blacked out, portions of the prior program will also be blacked out. On
the other hand, if the sequence is begun at the beginning of the program
to be blacked out, subscribers may find it objectionable to receive a
portion of the local event and then to observe that the program is being
blacked out.
In the direct broadcast satellite system in which the present invention is
employed, each receiver unit is provided with a memory for storage of a
designation code representing its geographic location, and a memory for
storage of indications of tiers upon which programs to be blacked out are
to be distributed. This latter memory is referred to as the blackout
memory and stores the blackout tier indications.
After each receiver unit is provided with a designation code, the receiver
units are globally addressed. Each receiver unit having a selected
designation code stored therein is provided with a blackout tier
indication for storage. When a program is selected for viewing, the
receiver unit compares the program tier indication distributed with the
program and the stored blackout tier indication. If the indications match,
the selected program cannot be displayed.
Thus, the present invention relates to a method designed for use in a
direct broadcast satellite system where, in response to a single command
sequence (program tier indication) from the transmission end, all
previously defined receiver units (having a stored blackout tier
indication matching the program tier indication) may be simultaneously
prevented from displaying a particular program. This method is
particularly suitable for blacking out programs in selected geographic
areas, but may be applied for other purposes. Because the method is
particularly suitable for geographic blackouts, it will be described
herein as applied to that purpose. However, the invention should not be
construed as limited thereto.
It is, therefore, a prime object of the present invention to provide a
method for use in a direct broadcast satellite system for simultaneously
blacking out a program for all receivers in a designated geographic area.
It is another object of the present invention to provide a method for use
in a direct broadcast satellite system for simultaneously blacking out a
program wherein each receiver unit is provided with a storable designation
code representing the geographic area in which the unit is located.
It is another object of the present invention to provide a method for use
in a direct broadcast satellite system for simultaneously blacking out a
program for all receivers in a particular geographic area wherein blackout
tier indications are globally distributed for storage in all receiver
units having a particular stored designation code.
It is another object of the present invention to provide a method for use
in a direct broadcast satellite system for simultaneously blacking out a
program for all receivers in a particular geographic area in which the
program to be blacked out is broadcast with a program tier indication and
all receivers having a stored blackout tier indication matching the
transmitted program tier indication are prevented from displaying the
program.
In accordance with one aspect of the present invention, a method for
simultaneously preventing the display of a program by selected receivers
is provided for use in a direct broadcast satellite system. The system is
of the type including a plurality of receiver units, some of which are
selected as being unable to display a given program. Each unit comprises a
memory. Prior to the transmission of a program which cannot be displayed
by selected units, each unit is addressed and provided with a designation
code for storage in its memory. All receiver units are then addressed and
those having a selected designation code stored therein are provided with
given indication for storage. Each program is transmitted with an
associated program indication. Each of the receiver units, upon receiving
a transmitted program, compares the program indication transmitted with
the program and the stored indication. Receiver units having a stored
indication matching the transmitted program indication are unable to
display the transmitted program.
Each of the receiver units has a unique address code. An address code is
transmitted with the encrypted message including the designation code. A
particular receiver unit can decrypt the encrypted message only if the
transmitted address code transmitted therewith matches the address code of
the receiver.
All receiver units can be addressed using a global address. The global
address is transmitted with a message containing the selected designation
code and given indication. Each receiver having a stored designation code
matching the designation code in the message stores the given designation
in the message.
The given indication comprises a plurality of bits. The memory comprises a
bit map memory.
In accordance with another aspect of the present invention, a method for
simultaneously blacking out a program from all receiver units in a
selected geographic area is provided for use in a direct broadcast
satellite system. The system is of the type including a plurality of
receiver units in various geographic areas. Each receiver unit has a
designation code memory and a blackout tier memory. Each receiver unit is
separately addressed and provided with a designation code for storage in
its designation code memory. Different designation codes represent
different geographic areas. Each designation code is selected in turn, and
for each designation code, a blackout tier indication is provided for
storage in the blackout tier memory of each receiver unit having a
matching designation code stored in its designation code memory. A signal
is transmitted to all receiver units including various programs, each of
which is accompanied by a program tier indication. Each receiver unit,
upon receiving the transmitted signal, compares the program tier
indication accompanying each program with the blackout tier indication in
its blackout tier memory. Any receiver unit having a stored blackout tier
indication corresponding to the transmitted program tier indication
accompanying a program is unable to display that program.
The transmitted signal includes a data stream. The data stream includes a
plurality of addressable portions. The blackout tier indication is
provided by generating an addressable portion addressed to all receiver
units commanding all receiver units having a given stored designation code
to store the blackout tier indication in the addressed portion.
Each of the receiver units has a unique address. Each receiver unit is
addressed by incorporating the address thereof in the addressable portion
which includes the designation code for the addressed receiver unit, as
well as a message for the receiver unit to enter the designation code into
its designation code memory.
In accordance with another aspect of the present invention, a receiver unit
is provided for use in a direct broadcast satellite system. The system
includes a plurality of receiver units and a transmission station for
generating a composite television signal including program information
including programs on a plurality of tiers, and an addressable data stream
including program tier indications for each program tier, designation code
information addressable to a particular receiver unit, and globally
addressed blackout tier indications, the receiver comprising means for
receiving the composite television signal, means for locating the portion
of the addressable data stream containing the designation code information
addressed to the receiver unit, means for storing the designation code
information, means for locating the globally addressed blackout tier
indication corresponding to the stored designation code information, means
for selecting a program for display, means for obtaining the program tier
indication for the selected program, means for comparing the program tier
indication with the stored blackout tier indication, and means for
displaying the selected program if said compared indications do not match.
Claims
We claim:
1. A method for simultaneously preventing the display of a program by
selected receiver units in a direct broadcast satellite system of the type
including a plurality of receiver units each comprising a tier
authorization memory, a designation code memory and a black-out code
memory, the method comprising the steps of, prior to the transmission of a
program the display of which is to be prevented, separately addressing
each receiver unit, providing each addressed receiver unit with a tier
authorization code for storage in its tier authorization code memory and
providing each addressed receiver unit with a designation code for storage
in the designation code memory of the receiver unit, globally addressing
all receiver units and transmitting a designation code and a corresponding
black-out code, a receiver unit storing the transmitted black-out code in
its black-out code memory if the transmitted designation code matches the
designation code previously stored in the receiver designation code
memory, transmitting a program with a program tier indication, each of the
receiver units, upon receiving the transmitted program, comparing the tier
indication with the stored black-out code to determine if the program is
to be blacked-out, if the program is not to be blacked-out, comparing the
transmitted tier indication with the stored tier authorization code to
determine if the program is authorized and displaying the program if it is
not to be blacked-out and is authorized.
2. The method of claim 1, wherein the provided designation code is
transmitted in an encrypted message and wherein the step of storing and
designation code comprises the step of decrypting the message to obtain
the designation code.
3. The method of claim 2, wherein each of the receiver units has a unique
address code and wherein an address code is transmitted along with the
encrypted message and further comprising the step of decrypting the
encrypted message only if the address code transmitted therewith matches
the address code of the receiver.
4. The method of claim 1, wherein the blackout tier indication comprises a
plurality of bits and wherein the memory comprises a blackout bit map
memory.
5. A method for simultaneously preventing the display of program from all
receiver units in a particular geographic area for use in a direct
broadcast satellite system of the type including a plurality of receiver
units in various geographic areas, each receiver unit having a tier
authorization memory, a designation code memory and a black-out bit map
memory the method comprising the steps of addressing each receiving unit
and providing same with a designation code for storage in the designation
code memory of the receiver unit, different designation codes representing
different geographic areas and providing a tier authorization for storage
in the tier authorization memory of the receiver, selecting each
designation code and, for each selected designation code, providing a
black-out code to be stored in the black-out bit memory of each receiver
unit having the selected designation code stored in the designation code
memory of the receiver unit, transmitting a signal comprising a program
accompanied by a program tier indication to all receiver units, each
receiver unit, upon receiving the signal, comparing the program tier
indication and the black code stored in the black-out bit memory to
determine if the program is to be blacked-out if the program is not to be
blacked-out, comparing the program tier indication with the stored tier
authorization code to determine if the program is on an authorized tier,
displaying the program if it is not to be blacked-out and is on an
authorized tier.
6. The method of claim 5, wherein said signal comprises a data stream
comprising a plurality of addressable portions and wherein the step of
providing a blackout code comprises the steps of generating an addressable
portion addressed to all receiver units and containing a blackout code,
and commanding all receiver units having a given stored designation code
to store the blackout code.
7. The method of claim 6, wherein each of said receiver units has a unique
address and wherein the step of providing a blackout code comprises
addressing a message to a particular receiver unit, said message
comprising a command to enter a particular designation code into the
designation code memory of the addressed unit.
8. A receiver for use in a direct broadcast satellite system of the type
including a plurality of receiver units and a transmission station
generating a composite television signal including program related
information including programs on a plurality of tiers and a data stream
including a program tier indication for each program, portions addressable
to particular receivers comprising tier authorization codes and
designation codes for storage in the addressed receiver units, and
globally addressable portions including designation codes and
corresponding black-out codes, the receiver unit comprising means for
receiving composite television signals, means for locating the portion of
the data stream addressed to the particular receiver unit, means for
storing a designation code in the addressable portion, means for storing
the tier authorization code in the addressable portion, means for locating
the globally addressed portion of the data stream containing a designation
code corresponding to the stored designation code, means for storing the
black-out code in the globally addressed portion associated with a
designation code matching the previously stored designation code, means
for selecting a program, means for comparing the broadcast program tier
indicating for the selecting program with the stored black-out code to
determine if the selected program is to be blacked-out, means for
comparing the program tier indication with the stored tier authorization
code, to determine if the selected program is authorized and means for
displaying the selected program if the program is not to be blacked-out
and is authorized.
9. The receiver of claim 8 wherein the designation code is transmitted in
an encrypted message and wherein the means for storing the designation
code comprises means for decrypting the message to obtain the designation
code.
10. The receiver of claim 9 wherein each of the receiver units has a unique
address code and wherein the address code is transmitted as a part of the
portions addressable to particular receivers and further comprising means
for storing the address code and means for decrypting the encrypted
message only if the address code transmitted with the message matches the
address code stored in the receiver units address code storage means.
11. The method of claim 8 wherein the black-out code comprises a plurality
of bits and wherein the means for storing the black-out code comprises a
black-out bit map memory.
Description
To these and to such other objects which may hereinafter appear, the
present invention relates to a geographic blackout method for use in a
direct broadcast satellite system as set forth in detail in the following
specification and recited in the annexed claims, taken together with the
accompanying drawings, wherein like numerals refer to like parts, and in
which:
FIG. 1 is a diagram schematically representing the blackout bit map memory,
the blocking bit map memory, and authorization bit map memory of a typical
subscriber receiver unit of the present invention;
FIG. 2 is a flow chart of the procedure whereby the blackout code memories
of the subscriber receiver units in various geographic areas are set and
reset;
FIG. 3 is a flow chart of the operations of the receiver unit in setting
its designation code memory and blackout bit map memory;
FIG. 4 is a flow chart of the operations which permit a subscriber receiver
unit to decide whether a particular program should be blacked out;
FIG. 5 is a schematic diagram illustrating the composite television
broadcast signal distributed through the direct broadcast satellite
network in which the present invention is utilized; and
FIG. 6 is a block diagram of the receiver unit of the present invention,
including the tuner section and the addressable control decoder section.
The details of the direct broadcast satellite network in which the blackout
method of the present invention is employed, including an explanation of
the transmission end equipment, the terminal end equipment, and the signal
transmission system employed for communications between the two are set
forth in co-pending U.S. patent application Ser. No. 4,599,647, issued
July 8, 1986 in the names of Ashok George and John Jeffers, entitled
"Receiver With Interface For Interaction With Controller-Decoder" and in
U.S. Pat. No. 4,739,510, issued Apr. 19, 1988 in the names of Joseph
Glaab, Donald Horne, John Jeffers, and Wayne Mundy, entitled "Direct
Broadcast Satellite Signal Transmission System."
An explanation of the basic cryptographic method used in the direct
broadcast satellite network disclosed above can be obtained from
co-pending U.S. patent application Ser. No. 665,114 filed Oct. 26, 1984 in
the name of Donald Horne, and entitled "Cryptographic System For Direct
Broadcast Satellite Network." Certain improvements in the cryptographic
system used in the direct broadcast satellite network can be obtained from
co-pending U.S. patent application Ser. No. 710,385 filed Mar. 11,1985 in
the names of Donald Horne and John Jeffers, entitled "Cryptographic System
Using interchangeable Key Block and Selectable Key Fragments."
The reader is also referred to co-pending U.S. patent application Ser. No.
710,466 filed Mar. 11, 1985 in the name of Donald Horne, entitled "Program
Blocking Method For Use In Direct Broadcast Satellite SysteM" which
describes the use of a blocking bit map in a direct broadcast satellite
system having impulse pay-per-view capability. All of the above-captioned
applications are assigned to the assignee hereof.
The direct broadcast satellite network of the present invention is designed
to supply television programming to a large number of subscriber receiver
units distributed in various geographic areas. Each geographic area may
have a large number of subscriber receiver units contained therein.
Each of the subscriber units is supplied, via satellite, with a number of
different programming tiers. Each subscriber, upon entering the network,
obtains a receiver unit which includes a signal tuner and modulation
section and an addressable controller-decoder for use in conjunction with
the subscriber's television.
Each subscriber chooses one or more of the programming tiers to be received
on a subscription basis. The subscriber pays the system operator a
periodic fee, for example monthly, which entitles him/her to view the
programs on the tiers he/she has selected and paid for. Other tiers of
programming can be paid for on impulse on a pay-per-view basis. Programs
eligible for viewing on an impulse pay-per-view basis are previewable -by
the subscriber by permitting the subscriber to view the beginning of the
program, for example, the first five minutes thereof, after which the
subscriber must decide whether to pay for the privilege of viewing the
remainder of the program.
In order to view a program eligible for an impulse pay-per-view
transaction, the subscriber enters a secret pass code on a keyboard
associated with the tuning section of the receiver unit. The addressable
controller-decoder connected therewith will enter certain information into
a memory relating to the identification number of the program being
viewed, the time and date of the viewing, and the cost which the
subscriber will have to pay for the privilege of viewing the program.
Periodically, the addressable controller-decoder will receive instructions
from the system operator to forward the accumulated data relating to the
previous impulse pay-per-view transactions and provide same to the system
operator for billing purposes. This can be done in one of two ways. If the
addressable controller-decoder has telephone communications capability,
that is, provided with a modem connected to a telephone line, and the
necessary circuitry to operate the modem, the controllable addressable
decoder will call a computer located at the transmission end and, after
the appropriate identification procedure, will transfer the information
concerning the impulse pay-per-view transactions stored in the addressable
controller-decoder memory to the computer at the transmission end. That
computer will then periodically generate a bill which will be mailed to
the subscriber.
If the addressable controller-decoder does not have telephone
communications capability, a credit card type device can be utilized for
billing purposes. The credit card type device is essentially a memory on a
card which is inserted into a slot provided on the addressable
controller-decoder. Upon receiving the appropriate commands from the
transmission end, the addressable controller-decoder will transfer its
stored information concerning the impulse pay-per-view transactions onto
the card memory. The subscriber will then mail the card memory to the
system operator who will then access the card memory to ascertain the
impulse pay-per-view transactions and provide the subscriber with a bill
in accordance therewith.
Certain programming, whether eligible through subscription or through
impulse pay-per-view transaction, must be prevented from display on
designated receiver units. Such programming may incorporate content which
is objectionable for some reason or may relate to particular programming,
such as sporting events, which are taking place locally and must be
blacked out. In order to maintain attendance at such sporting events at a
high level, the program is distributed with the restriction that the
program will not be viewable within the geographic area in which it is
taking place.
The present invention relates to a method for preventing the display of
selected programming by designated receiver units. It is particularly
adaptable for use in simultaneously blacking out particular programs in
designated geographic areas.
In order to black out all the receiver units in a particular geographic
area, it is normally necessary to access each unit and provide same with
the necessary blackout instructions. Since there may be hundreds of
thousands or even millions of receiver units in a particular geographic
area, accessing each unit in order to provide it with blackout information
will require a relatively long time. If instructions to black out
programming on a particular tier are distributed prior to the commencement
of the program to be blacked out, this may interrupt the viewing of the
prior program, which is normally not blacked out, a result which is to be
avoided. On the other hand, if the distribution of the blackout command
information does not take place until the program to be blacked out
commences, certain viewers will be able to view the beginning portion of
the program and will be blacked out a few minutes into the program, which
may cause annoyance.
The present invention overcomes these problems by providing each receiver
unit and, particularly the addressable controller-decoder portion thereof,
with a blackout tier indication memory in the form of a blackout bit map
memory and a receiver unit designation code memory. Each unit is addressed
and provided with a designation code, in this case, a code which reflects
the geographic location of the receiver unit. The designation code is
stored in the unit. The units are then globally addressed and provided
with a selected designation code and a blackout tier indication. The
blackout tier indication represents a particular programming tier to be
blacked out on all receiver units having the selected designation code. If
the stored designation code matches the designation code being
transmitted, the blackout tier indication is stored in the receiver
blackout bit map memory. This takes place prior to the transmission of the
program to be blacked out.
Each program is transmitted in association with a program tier indication.
If the program is to be blacked out in a particular geographic area
represented by a given designation code, the program tier indication will
match the blackout tier indication previously stored in all receiver units
having that stored designation code. Upon receiving a program, each
receiver unit compares the program tier indication transmitted therewith
and the blackout tier indication in its blackout bit map memory. If the
indications match, the program cannot be displayed. Otherwise, the program
is displayed as usual. Thus, all receivers in a selected geographic area
will be blacked out to be prevented from displaying the program.
Each receiver unit also has a tier authorization memory in the form of an
authorization bit map memory and a tier blocking memory in the form of a
blocking bit map memory. Indications relating to programming tiers not
selected for subscription are stored in the authorization bit map memory.
Indications relating to tiers to be blocked by the system operator are
stored in the blocking bit map memory. Authorization tier indications and
blocking tier indications are distributed in addressable portions of the
data stream in the composite television signal in the same way as the
designation code.
While the various bit map memory facilities are referred to herein as
separate memories, it should be understood that same may, in reality, be
different areas of the same memory circuit.
FIG. 1 graphically depicts the manner in which the authorization bit map
memory, blocking bit map memory, and blackout bit map memory are utilized
within the addressable controller-decoder. Each bit map is an array of
bits equal to the number of programming tiers, for example, 32 bits
corresponding to 32 programming tiers. Thus, each bit represents a tier.
Each bit in each array is tested with each corresponding bit in each other
array to determine whether programming on a selected tier may be
displayed.
Only six tiers of programming, S.sub.0..S.sub.5, are shown for purposes of
illustration, but it is understood that many more tiers of programming can
be utilized. Programming tiers S.sub.0 and S.sub.3 are programming tiers
which have been paid for by subscription and contain, for example,
commercial programming which can be viewed without further action on the
part of the subscriber.
Programming tiers S.sub.1 and S.sub.2, for example, contain "R" rated and
"PG" rated movies thereon, respectively. Both programming tiers S.sub.1
and S.sub.2 are eligible for impulse pay-per-view transactions as the
addressable controller-decoder has previously received instructions
authorizing the viewing of these tiers on this basis. However, the
subscriber does not wish to have certain members of the household view the
"R" rated movies on programming tier S.sub.1. This has been previously
communicated to the system operator who has then provided the subscriber's
addressable controller-decoder with particular commands such that the
blocking bit map contained in the subscriber's addressable
controller-decoder memory has been set to block the display of programming
tier S.sub.1, even if the appropriate passcode is entered into the
controller which would normally permit the subscriber unit to display the
program and charge the subscriber for the privilege.
Programming tiers S.sub.3 and S.sub.4 contain sports programs thereon.
Programming tier S.sub.3, like tier S.sub.0, is part of the subscription
and, hence, need not be authorized for impulse pay-per-view transactions.
It is not blocked or blacked out and, therefore, can be viewed. However,
the programming on tier S.sub.4 has been blacked out of the geographic
area in which the subscriber unit is situated. Accordingly, the
addressable controller-decoder will not permit the programming on tier
S.sub.4 to be displayed.
The programming on tier S.sub.5, like the programming on tier S.sub.2, is
eligible for impulse pay-per-view transactions. Since this programming has
not been blocked and has not been blacked out, it can be viewed by the
entrance of the appropriate passcode at the keyboard of the receiver unit.
The program will then be displayed and the subscriber charged for the
privilege.
Control data is distributed to the subscriber units through a data stream
which is situated in consecutive horizontal blanking intervals within the
composite television broadcast signal. The data stream is described in
detail below In general, the data stream includes a header packet which
contains a group address, certain program related information, including a
program tier indication for each program being distributed, and certain
impulse pay-per-view information such as an identification number relating
to a particular program eligible for an impulse pay-per-view transaction
and the cost of viewing same. This type of information is generally
applicable to all receiver units in the addressed group.
The data stream also includes a plurality of addressable packets containing
encrypted messages applicable to the control of particular subscriber
units within the addressed group. Each subscriber unit has an individual
address number. An addressable packet is addressed to a particular
subscriber unit by including therein the subscriber unit's individual
address number. Only the subscriber unit with that individual address
number can receive and decode the message in that addressed packet.
The addressed packet may contain a selected one of several different
messages along with the information necessary for the particular addressed
subscriber unit to decode the message. For example, a particular message
may cause the addressed subscriber unit to load a designation code into
its designation code memory. Another message may cause the storage of
blackout tier indications into a blackout bit map memory. Other messages
may cause an addressed receiver unit to be provided with authorization
tier indications to set its authorization bit map memory, or with blocking
tier indications to set its blocking bit map memory.
It is also possible to utilize an addressable packet to send a global
message, that is, a message applicable to the control of all receiver
units within the addressed group. The global message is sent in clear or
unencrypted form. In this case, a global address, for example all ones, is
utilized. Such a message, for instance, may be a command for all
subscriber units in the group having a particular stored designation to
perform a certain function.
The system of the present invention is initialized by separately addressing
each subscriber unit in each group within the network and commanding each
addressed subscriber unit to enter a particular designation code,
contained within a message in the addressable packet, in its designation
code memory. Different geographic areas are assigned different designation
codes. Thus, all subscriber units in a particular geographic area will
have the same designation code stored in their designation code memories.
After the designation codes are stored in all subscriber units, each
designation code is selected, in turn, and the blackout bit map memory of
each subscriber unit having the selected designation code is set (or
reset). This is accomplished by sending a global message in an addressable
packet of the data stream in which a global address, such as a series of
ones, is contained commanding all subscriber units in the system to load a
particular sequence of bits, which form the blackout tier indication, into
their blackout bit map memory if the designation code previously stored in
the unit matches the designation code in the message. After this occurs,
the next designation code will be selected and a global message will be
sent instructing all subscriber units having that designation code to set
or reset their respective blackout bit map memories with a particular
blackout tier indication. The process continues until the blackout bit map
memories of all receivers in each geographic area have been set. This is
illustrated in FIG. 2.
As illustrated in FIG. 3, each receiver unit receives the composite
television signal and looks for an addressed packet with its unit address.
Each addressed packet with a unit address contains a message type
indication, an encrypted message, and decryption information. One message
type represents a command to set the designation code memory with a
designation code contained in the message. Other message types represent
commands to set the authorization bit map memory, blocking bit map memory,
or perform other functions. The receiver unit decrypts the message and
performs the designated function, i.e., store the designation code in its
designation code memory.
A global message, that is, an addressed packet with a global address will
then be sent. The message contains a designation code and a blackout tier
indication in clear or unencrypted form. If the stored designation code
matches the designation code in the designation memory, the receiver unit
will store the blackout tier indication in its blackout bit map memory.
Each program broadcast over the composite television signal has a header
packet associated therewith which contains the program tier indication
associated with that program.
As illustrated in FIG. 4, when the composite television signal is received
by the subscriber unit, the subscriber will select a program for display.
The subscriber unit located at the header packet in the addressable data
stream corresponding to the selected program and obtains the program tier
indication therein. The subscriber unit will then access its blocking bit
map memory. It will compare the program tier indication from the header
with the stored blocking tier indication. If the indications match, that
is, if there is a "one" bit at the same location, the program will be
blocked and cannot be displayed by the receiver unit.
Next, the blackout bit map memory will be accessed and the program tier
indication compared with the blackout tier indication. If the indications
match, that is, if there is a "one" bit in the program tier indication at
the same location as the "one" bit in the blackout bit map memory, the
program will not be displayed.
Finally, the authorization bit map memory is accessed. If the program tier
indication matches the authorization tier indication, an impulse
pay-per-view transaction must take place before the program can be viewed.
Otherwise, the program is within the subscription and can be displayed
without further action on the part of the subscriber.
FIG. 5 schematically represents the type of composite TV signal distributed
by the direct broadcast satellite network. This signal comprises a
plurality of active video portions, sync portions, and horizontal blanking
interval portions. A data stream, including digitized audio signals and
control data, is inserted into consecutive horizontal blanking intervals
of the composite television signal.
The data stream includes a run-in code portion, an addressable data stream
portion, an encrypted audio signal portion, an audio code portion
indicating whether the audio channels being broadcast are stereo or
bilingual, a video inversion code required to descramble the video
signals, and a spare bit portion. The addressable data stream portion
includes a header packet for each program being distributed and a
plurality of addressable packets. As mentioned above, global information
may be contained in an addressable packet containing a global address, for
example, all ones. Information relating to the control of specific
receiver units is contained in addressable packets including the unique
address number of the particular receiver unit.
Each of the addressable packets includes an address portion, which is
either global in nature or specific to a particular subscriber. In packets
addressed to specific subscriber units, the address portion is followed by
an encrypted message and information which will enable the addressed
subscriber unit to decode the message.
Encrypted messages of various types, containing a variety of different
kinds of control data, can be distributed in this fashion. For purposes of
this application, it is sufficient to understand that one type of
encrypted message may be a command to the addressed subscriber unit to
load a particular designation code into its designation code memory.
Another type of encrypted message may be a command for the subscriber unit
to load a particular blocking tier indication into its blocking bit map
memory. Still another type of encrypted message may be a command to set
the authorization bit map memory with an authorization tier indication.
One type of message is illustrated as addressable packet 1. This packet
includes the subscriber unit address for one specific unit, an indication
of the message type (i.e., command to set designation code memory), the
message (designation code to be stored in memory), and the necessary
information for the addressed unit to decrypt the message.
A globally addressed message is illustrated as addressable packet 2. This
message contains a global address (meaning it is applicable to all
receiver units in the system) and an indication of the message type (a
command to set the blackout bit map memory if the designation code in the
message matches the designation code previously stored in the designation
code memory). This addressable packet also contains a message containing
the designation code to be compared and the blackout tier indication to be
stored.
After the broadcast of the program to be blacked out, another global
message is sent to all receiver units through the data stream. This global
message commands all receiver units to reset their respective blackout bit
map memories to zero, thereby erasing the blackout information. Once this
occurs, the programming on the tier previously designated for blackout
will be able to be viewed. In this manner, the blackout bit map memory can
be set and reset as required.
While, for simplicity, the present application has discussed the blackout
of a single program tier at a time, it should be appreciated that several
tiers can be blacked out at the same time by distributing a blackout tier
indication which includes "one" bits at locations representing several
tiers. For example, blacking out tiers two and four would require a
thirty-two bit stream with "ones" at the second and fourth bit. Thus, the
term "indication" as used herein refers to a bit stream having ones in
positions which correspond to one or more tier numbers.
FIG. 6 is an overall block diagram of the receiver unit of the present
invention. The receiver unit includes a tuner section, generally
designated A, which is described in detail in previously mentioned U.S.
Pat. No. 4,599,647 and an addressable controller decoder section,
generally designated B, which described in detail in the aforementioned
U.S. Pat. No. 4,739,510. Tuner section A is connected to receive the
output from a Low Noise Block circuit (not shown), operably connected to
an antenna (also not shown) for receiving direct broadcast signals from a
satellite transponder. Tuner circuits 10 select the frequency of the
composite television signal of interest, under the control of
microcomputer 12, and transfer the tuned signal of the data processing
circuit 14 of decoder B. Microprocessor 12 is linked to an input keyboard
16 and a display 18 such that the user can enter various commands into the
receiver and read information from the display. Microcomputer 12 is
connected by means of a two way link 20 with the microcontroller 22 of
decoder B. Data link 20 permits the tuner section A and the decoder B to
communicate with each other as described in detail in U.S. Pat. No.
4,599,647.
Microcontroller 22 controls the various functions of decoder B. Data
processing circuit 14 separates the addressed data messages from the
remainder of received composite television signal. Microcontroller 22
compares the address information in the addressed message with the address
previously stored in memory 24. The comparison takes place in comparison
circuits 26. If a match is indicated, the data is decrypted in decryption
circuit 28 and either stored in memory 24 or used by comparison circuits
26 to determine if there is an appropriate match which permits the
programming to be displayed on a television.
If it is indicated that the program is to be displayed video processing
circuit 30 is actuated to process the video signals and transfer them to
video control circuit 32. The output from video control circuit 32 is
transferred back into tuning section A to the TV modulator circuit 36. The
TV modulator circuit 36 also receives the audio signal from audio control
circuit 34 which, in turn, receives same from data processing circuit 14.
The output of TV monitor circuit 36 is fed through a RF switch 38,
controlled by microcomputer 12, to the television.
Memory 24, in addition to the address of the receiver unit, includes memory
sections in the form of bit maps for the storage of tier authorization
codes, designation codes, blocking codes and blackout codes, as described
above. These code memories are preferably in the form of separate bit
maps. While memory 24 is illustrated as having different bit map sections,
it may in fact encompass several different memories instead of a single
memory with different sections designated to store different codes.
It will now be appreciated that the present invention permits all
subscriber units located in a particular geographic area to black out a
particular program upon the receipt of a given program tier indication
associated with the program. This can occur because the particular
subscriber units within the geographic area to be blacked out have
previously been provided with a given blackout tier indication. The
subscriber units within each geographic area have previously been loaded
with designation codes representing the area in which the unit is located.
Since the designation codes and the blackout tier indications are
distributed and stored prior to the broadcast of the programming to be
blacked out, this can be done over a relatively long time without
disrupting the operation of the system. Setting up the system in this way
permits the program to be blacked out in all receiver units within the
designated geographic area simultaneously.
While only a single preferred embodiment of the present invention has been
disclosed herein for purposes of illustration, it is obvious that many
variations and modifications could be made thereto. It is intended to
cover all of these variations and modifications which fall within the
scope of the present invention, as defined by the following claims:
Top